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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>A. León);</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>BETTER: Better rEal-world healTh-DaTa distributEd analytics Research platform⋆</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Ana León Palacio</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>José F. Reyes Román</string-name>
          <email>jreyes@vrain.upv.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Oscar Pastor</string-name>
          <email>opastor@dsic.upv.es</email>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Universitat Politècnica de València</institution>
          ,
          <addr-line>Camí de Vera s/n 46022 Valencia</addr-line>
          ,
          <country country="ES">Spain</country>
        </aff>
      </contrib-group>
      <volume>000</volume>
      <fpage>0</fpage>
      <lpage>0002</lpage>
      <abstract>
        <p>Over the last few years, data-driven medicine has gained increasing importance in terms of diagnosis, treatment, and research due to the exponential growth of healthcare data. The linkage of cross-border health data from various sources, including genomics, and analysis via innovative Artificial Intelligence (AI) approaches will allow a better understanding of risk factors, causes, and the development of optimal treatment in different disease areas. However, the reuse of patient data is often limited to data sets available in a single medical center. The main reasons why health data are not shared across institutional boundaries rely on ethical, legal, and privacy aspects and rules. Therefore, in order to (1) enable the sharing of health data across national borders, (2) fully comply with the current GDPR privacy guidelines/regulations, and (3) innovate by pushing research beyond state of the art, BETTER proposes a robust decentralized privacy preservation infrastructure which will empower researchers, innovators, and healthcare professionals to exploit the full potential of larger sets of multisource health data through tailored AI tools useful to compare, integrate, and analyze in a secure, cost-effective fashion; with the end goal of supporting the improvement of citizen health outcomes. In detail, this interdisciplinary project proposes the co-creation of three clinical use cases involving seven medical centers located in the EU and beyond, where sensitive patient data, including genomics, are made available and analyzed in a GDPR-compliant mechanism via a Distributed Analytics (DA) paradigm called the Personal Health Train (PHT). The main principle of the PHT is that the analytical task is brought to the data provider (medical center), and the data instances remain in their original location. In this project, two mature implementations of the PHT (PADME and Vantage6), already validated in real-world scenarios, will be fused to build the BETTER platform.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Health Data</kwd>
        <kwd>Personal Health Train</kwd>
        <kwd>Artificial Intelligence</kwd>
        <kwd>Distributed Analytics</kwd>
        <kwd>PADME</kwd>
        <kwd>Vantage61</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>1.1.</p>
      <sec id="sec-1-1">
        <title>Context and Motivation</title>
        <p>Integrating vast arrays of health data from genomics and electronic health records through
advanced artificial intelligence (AI) technologies has revolutionized our understanding of diseases,
risk factors, and therapeutic strategies [1]. However, the utility of data in medical research is
profoundly dependent on its volume and diversity. This is especially true when studying rare
diseases and could be solved by sharing data among clinical centers. Nevertheless, sharing patient
data across institutions is conditioned by ethical, legal, and privacy concerns [2].</p>
        <p>Current data protection regulations, such as the General Data Protection Regulation (GDPR),
prohibit data centralization for analysis because of privacy risks, such as the accidental disclosure of
personal data to third parties. Overcoming these challenges requires moving from a centralized to a
decentralized paradigm that enables the secure and efficient exchange of health information across
borders while ensuring compliance with privacy regulations.</p>
        <p>This shift entails complex technical challenges, including orchestrating decentralized
computation, ensuring secure audibility, and harmonizing heterogeneous clinical and genomic
datasets. Addressing these challenges requires a coordinated, long-term effort involving the
development, deployment, and validation of federated learning infrastructures that can operate in
real-world clinical settings.
1.2.</p>
      </sec>
      <sec id="sec-1-2">
        <title>Current Approach</title>
        <p>The BETTER project2 proposes a decentralized infrastructure that uses Distributed Analytics (DA)
through a mechanism known as the Personal Health Train (PHT) [3]. The PHT model ensures that
analytical processes are executed at the data provider's site, allowing data to remain securely within
its original location. This model can be illustrated using a railway system analogy, where the key
infrastructure components include Trains, Stations, and a Central Service (Fig. 1).</p>
        <p>
          Trains encapsulate code to execute analytical tasks at distributed data nodes, known as Stations.
As they travel from one Station to another, they process data locally, leveraging the available
information at each stop to incrementally build the final analysis result. A Station is a node
(institution, hospital, or department) within the distributed architecture that securely stores
confidential data and executes Train operations. Each Station functions as an independent and
autonomous unit, managing permission requests to control access to its confidential data. The
Central Service includes procedures for Train orchestration, operational logic, business logic, data
management, and discovery. The Central Service offers: (
          <xref ref-type="bibr" rid="ref1">1</xref>
          ) a metadata repository for efficient data
discovery; (
          <xref ref-type="bibr" rid="ref2">2</xref>
          ) management tools for Train creation, secure transmission to Stations, orchestration,
monitoring, and debugging; and (
          <xref ref-type="bibr" rid="ref3">3</xref>
          ) a repository of pre-trained Trains that healthcare professionals
can directly apply to their data, enabling them to obtain results from an AI-based method trained
iteratively on data from multiple institutions.
1.3.
        </p>
      </sec>
      <sec id="sec-1-3">
        <title>The Technology Behind the BETTER Project</title>
        <p>The BETTER project integrates two established implementations of the PHT: PADME (Platform
for Analytics and Distributed Machine Learning for Enterprises)3 and Vantage6 (priVAcy preserviNg
federaTed leArninG infrastructurE for Secure Insight eXchange) [4]. Fig. 2 shows how PADME and
VANTAGE6 are connected to create the BETTER infrastructure.
2 https://www.better-health-project.eu/
3 https://padme-analytics.de/</p>
        <p>Both implementations have already demonstrated their effectiveness in various clinical settings,
including oncology [5], diabetes [6], and cardiovascular diseases [7]. These works show that
federated learning in the healthcare domain is technically feasible.</p>
        <p>To ensure the ethical and trustworthy use of artificial intelligence, the BETTER project adopts a
comprehensive strategy to address AI bias throughout the development lifecycle. All AI tools are
developed following the European Commission’s Trustworthy AI Guidelines, with specific attention
to fairness, transparency, and robustness. Co-creation with clinicians ensures that domain
knowledge is integrated into the design process, helping to identify and correct biases. Before model
training and testing, clinical datasets undergo rigorous curation, including pseudonymization,
semantic annotation with standardized ontologies, and data quality checks for completeness,
consistency, and integrity. This process is complemented by the FAIRification of metadata to ensure
interoperability and reproducibility. Together, these practices establish a robust foundation for the
development of clinically reliable AI tools.
1.4.</p>
      </sec>
      <sec id="sec-1-4">
        <title>Participants</title>
        <p></p>
        <p>BETTER is a Horizon Europe project with a duration of 42 months and the participation of 14
organizations from eight countries, including seven clinical institutions and seven technological
centers:
</p>
        <p>Clinical Institutions: Klinikum Der Universitaet Zu Koeln (UKK - Germany), Fundació de
Recerca Sant Joan de Déu (FDSJD - Spain), Azienda Socio-Sanitaria Territoriale
Fatebenefratelli Sacco (BUZZI - Italy), Fundació Docència i Recerca Mutua de Terrassa
(Spain), Instituto de Investigación Sanitaria - Hospital Universitario y Politécnico La Fe
(Spain), Institut Za Molekularnu Genetiku I Geneticko Inzenjerstvo (IMGGE - Serbia), and
Hadassah Medical Organization (HMO - Israel).</p>
        <p>Technological Centers: Datrix Spa (Italy), Universiteit Maastricht (UM - Netherlands),
Politecnico di Milano (POLIMI - Italy), Universitat Politècnica de València (UPV - Spain),
Universitetet i Tromsø - Norges Arktiske Universitet (UiT - Norway), Rheasoft ApS
(Denmark), and Noosware Bv (Netherlands).
1.5.</p>
      </sec>
      <sec id="sec-1-5">
        <title>Clinical Use Cases</title>
        <p>The project aims to apply these innovative DA methodologies to three clinical use cases: Pediatric
Intellectual Disability, Inherited Retinal Dystrophies, and Autism Spectrum Disorders. The
overarching goal is to harness the full potential of multisource health data, enabling researchers,
healthcare professionals, and innovators to conduct comprehensive analyses, integrate disparate data
types, and derive meaningful insights securely and cost-effectively.</p>
        <p>As shown in Fig. 3, seven medical centers will integrate, validate, and utilize the digital tools built
on top of the BETTER platform, where multiple data sources from different centers can be fused and
exploited to improve clinical outcomes.
1.5.1.</p>
      </sec>
      <sec id="sec-1-6">
        <title>Use Case 1: Integration of Genomic and Phenotypic Data from</title>
      </sec>
      <sec id="sec-1-7">
        <title>Pediatric Rare Diseases to Decipher Pathways of Intellectual Disability</title>
        <p>
          Intellectual disability (ID) is a common disorder characterized by significant limitations of
cognitive functions and adaptive behavior, with onset before age 18. This use case aims to (
          <xref ref-type="bibr" rid="ref1">1</xref>
          ) evaluate
and correlate the phenotypic, genomic, multi-omic, and clinical parameters between early-diagnosed
and later-diagnosed patients; (
          <xref ref-type="bibr" rid="ref2">2</xref>
          ) Improve diagnosis by identifying new genetic biomarkers that can
be used in newborn screening protocols; (
          <xref ref-type="bibr" rid="ref3">3</xref>
          ) Develop new tools based on Digital Twins Model to
define new diagnostic biomarkers, pathways, and therapeutic molecular targets.
        </p>
        <p>To such an aim, clinical data, brain images, genomic data (whole-exome, whole-genome
sequences), and biological data (cellular and molecular pathways) will be integrated. The participants
in this use case are the Hospital Sant Joan de Deu (medical leader), IMGGE, the Children's Hospital
Vittore Buzzi, and the Politecnico di Milano (technological leader).
1.5.2.</p>
      </sec>
      <sec id="sec-1-8">
        <title>Use Case 2: Accelerate Inherited Retinal Dystrophies Diagnosis using AI</title>
        <p>
          Inherited Retinal Diseases (IRDs) are a group of disorders characterized by the generally
progressive death or dysfunction of photoreceptors and retinal pigment epithelium (RPE) cells,
leading to loss of visual function, sometimes leading to legal blindness. An early molecular diagnosis
is necessary to confirm the clinical diagnosis and offer adequate care to patients. In addition,
developing new genetic analysis tools that allow the precise identification of the molecular cause of
disease is essential to improve the understanding of the pathophysiological mechanisms at the base
of the symptoms and open the doors to future therapies. This study aims to (
          <xref ref-type="bibr" rid="ref1">1</xref>
          ) identify pathogenic
genes and variants responsible for the IRDs, and (
          <xref ref-type="bibr" rid="ref2">2</xref>
          ) define existing genotype-phenotype correlations
to better understand the prognosis of patients and improve their clinical management.
        </p>
        <p>To such an aim, genomic data (gene panels, clinical exome, whole exome, whole genome), clinical
reports, and images will be integrated. The participants in this Use Case are the Hospital
Universitario La Fe de Valencia (medical leader), the Hadassah Medical Center, and the Polytechnic
University of Valencia (technological leader).
1.5.3.</p>
      </sec>
      <sec id="sec-1-9">
        <title>Use Case 3: Predicting the Risk of Self-Harm and Suicidal Behaviors in</title>
      </sec>
      <sec id="sec-1-10">
        <title>Patients with Autism Spectrum Disorders</title>
        <p>
          Autism Spectrum Disorders (ASD) are neurodevelopmental disabilities characterized by social,
communication, and behavioral challenges. Children and adolescents with ASD are at a substantially
higher risk of self-injurious and suicidal behavior compared to the general population (up to 9 times).
However, the causes of this increased risk remain largely unknown, and there is little knowledge
about the potential role of phenotypic, metabolic, genomic, and environmental factors. This use case
aims to (
          <xref ref-type="bibr" rid="ref1">1</xref>
          ) identify predictive phenotypic, genomic, and environmental risk factors of suicidality and
self-injury in ASD individuals; (
          <xref ref-type="bibr" rid="ref2">2</xref>
          ) Personalize prevention intervention plans to reduce self-injury and
suicidality in each ASD individual; and (
          <xref ref-type="bibr" rid="ref3">3</xref>
          ) Develop monitoring strategies to recognize signs of
vulnerability in ASD individuals that will lead to prevent strategies at an earlier stage and thereby
further reduce risk of self-harm and suicidal intentions.
        </p>
        <p>To such an aim, clinical, metabolic, environmental and demographic data, patient interviews, and
genomic data (epigenome and whole genome sequencing) will be integrated. The participants in this
Use Case are Hospital Universitario Mutua Terrassa (medical leader), Children's Hospital Vittore
Buzzi, and the Klinikum Der Universitaet Zu Koeln (UKK). UKK also participates as the technological
leader.</p>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>2. Project Objectives</title>
      <p>
        The BETTER project has five main objectives (
        <xref ref-type="bibr" rid="ref1">1</xref>
        ) Overcome cross-border barriers to health data
integration, access, FAIRification, and preprocessing; (
        <xref ref-type="bibr" rid="ref2">2</xref>
        ) Ensure health data fusion and integration;
(
        <xref ref-type="bibr" rid="ref3">3</xref>
        ) Deploy a distributed analytics framework for cross-border data processing and analysis; (
        <xref ref-type="bibr" rid="ref4">4</xref>
        )
Development of distributed tools leveraging artificial intelligence capabilities; (
        <xref ref-type="bibr" rid="ref5">5</xref>
        ) Include ethical,
legal and societal aspects (ELSA) in the AI lifecycle.
2.1.
      </p>
      <sec id="sec-2-1">
        <title>Objective 1: Overcome Cross-Border Barriers to Health Data Integration,</title>
      </sec>
      <sec id="sec-2-2">
        <title>Access, FAIRification, and Preprocessing</title>
        <p>The main aim of this first objective is to guide medical centers in collecting patients’ data
following a common schema to promote interoperability and the reuse of datasets in scope. This
includes collecting legal, ethical, and data protection authorizations and using well-established and
widely understood ontologies. Data pseudonymization will be performed as a default preprocessing
step to mitigate the risk of personal data leaks. Finally, a BETTER station will be installed at each
medical center, ensuring access to the relevant local datasets.
2.2.</p>
      </sec>
      <sec id="sec-2-3">
        <title>Objective 2: Ensure Health Data Fusion and Integration</title>
        <p>To gain the maximum from data, one of the important steps is integrating multiple data sources to
produce more consistent, accurate, and useful information than any single data source. The ambition
is to fuse several dimensions, including laboratory analysis, medical reports, drug therapy, imaging,
genomics, socio-demographic, geographical, and medical questionnaires.</p>
        <p>BETTER uses standardized ontologies (e.g., NCIT, LOINC, ICD-11) and a shared metadata schema
to ensure semantic alignment of data across sites. This enables data fusion and integration using the
proposed distributed framework in two directions: within a single medical center (local data fusion)
and across centers (distributed data fusion) by leveraging each other's historical datasets. Local data
fusion involves integrating data from multiple sources within a single institution. This type of data
fusion is useful when the data sources are heterogeneous, such as genomic, clinical, and phenotypic
data of the same patient. Distributed data fusion integrates data from multiple institutions, a fairly
novel discipline that includes removing potential biases due to different collection protocols or
techniques.
2.3.</p>
      </sec>
      <sec id="sec-2-4">
        <title>Objective 3: Deploy Distributed Analytics Framework for Cross-Border</title>
      </sec>
      <sec id="sec-2-5">
        <title>Data Processing and Analysis</title>
        <p>The ambition of this objective regards the deployment of BETTER, a privacy-by-design
infrastructure, to all medical centers connecting FAIR data sources and allowing federated data
analysis and machine learning. To effectively exploit multiple datasets via AI, a common schema and
ontology should be applied.
2.4.</p>
      </sec>
      <sec id="sec-2-6">
        <title>Objective 4: Development of Distributed Tools Leveraging Artificial</title>
      </sec>
      <sec id="sec-2-7">
        <title>Intelligence Capabilities</title>
        <p>To properly answer clinical needs and push data analysis boundaries beyond state-of-the-art,
tailored tools must be developed to exploit DA and AI within each use case. The tools will be
developed using a co-creation methodology where medical end-users closely collaborate with
researchers and technology providers, enabling the development of new concepts.
2.5.</p>
      </sec>
      <sec id="sec-2-8">
        <title>Objective 5: Include Ethical, Legal and Societal Aspects (ELSA) in the AI</title>
      </sec>
      <sec id="sec-2-9">
        <title>Lifecycle</title>
        <p>Most data science projects do not co-create or co-develop using a methodology that includes the
ethical, legal, and societal aspects (ELSA) involved in the data science lifecycle. In this objective, the
BETTER project will develop ELSA-awareness tools and methods for co-creating and co-developing
AI models and apply them to the proposed use cases. This will ensure the appropriateness and clinical
effectiveness of the developed AI tools while considering the safety, value, and sustainability of the
AI.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Impact and Expected Outcomes</title>
      <p>Overcoming the current barriers to data sharing and utilization, the BETTER project opens the
way to more accurate diagnoses, tailored treatments, and a deeper understanding of complex
diseases. The project's target groups are healthcare professionals, researchers, innovators, health
policymakers, and citizens.</p>
      <p>BETTER promotes a hands-on and experience-building approach towards the implementation of
cross-border data-sharing partnerships in the area of real-world health data. This contribution paves
the way for a European medical center data sharing and analysis network. The expected outcomes for
the BETTER project are:
 A public release of the platform implementation, which will reinforce two open-source
projects, namely PADME and Vantage6.
 Publication of the FAIRification pipelines, data catalogs, and ontologies to unleash the
potential of data exchange and reuse.
 Release of synthetic datasets to the community using generative AI techniques. This is
particularly valuable for developing and benchmarking models in data-restricted
scenarios.
 Finally, cross-border health data secure exchange and reuse require a solid and compliant
legal, ethical, and data protection framework. By enhancing existing templates, BETTER
will consolidate and publish a documentation folder useful and applicable for future
initiatives.</p>
    </sec>
    <sec id="sec-4">
      <title>4. Current Project Status and Future Work</title>
      <p>
</p>
      <p>The BETTER project is currently in its 14th month of work, having accomplished the following
milestones:
</p>
      <p>The ethical approvals and other documents required to execute the use cases have already
been approved.</p>
      <p>All clinical and technological partners have already installed the required technology, and
tests are already underway to ensure the correct connection to the platform.</p>
      <p>The FAIR database and the ETL process for each medical center are already finished.</p>
      <p>Currently, the medical and technological leaders of each use are working on the definition of the
analytical tasks, based on the datasets and their specific goals. Once the analytical tasks are defined,
the technological partners can start designing the AI algorithms (trains) according to the federated
learning paradigm to obtain the results. The infrastructure is being tested to ensure that all nodes
(technological and medical) are correctly connected and trains can move between stations and
execute simple tasks. The different interfaces to get statistics about the data are also under
development. In addition, since no real data is currently available, some synthetic datasets are being
generated to perform the tests without compromising security and privacy.</p>
    </sec>
    <sec id="sec-5">
      <title>5. Conclusion</title>
      <p>The BETTER project aims to provide a decentralized paradigm to enable the secure and efficient
exchange of health information across borders while ensuring compliance with privacy regulations.
Using the Personal Health Train model implemented by two open implementations (PADME and
Vantage6), the project will explore the feasibility of federated learning in three clinical use cases
(Pediatric Intellectual Disability, Inherited Retinal Dystrophies, and Autism Spectrum Disorders).
BETTER is a 42-month project financed by the European Union's Horizon Europe research and
innovation program, with 14 participants from eight countries, including seven clinical institutions
and seven technological centers. The overarching goal is to harness the full potential of multisource
health data, enabling researchers, healthcare professionals, and innovators to conduct
comprehensive analyses, integrate disparate data types, and derive meaningful insights securely and
cost-effectively.</p>
      <sec id="sec-5-1">
        <title>Acknowledgements</title>
        <p>This work is part of the Horizon Europe project BETTER. The BETTER project has received
funding from the European Union's Horizon Europe research and innovation program under grant
agreement No. 101136262. https://www.better-health-project.eu/.</p>
      </sec>
      <sec id="sec-5-2">
        <title>Declaration on Generative AI</title>
        <p>The author(s) have not employed any Generative AI tools.</p>
      </sec>
    </sec>
  </body>
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